Flow regulator



FIG. 1 is a top front perspective view of a flow regulator according to my design;

FIG. 2 is an elevational view thereof;

FIG. 3 is a top plan thereof; and,

FIG. 4 is a bottom view thereof.

The broken lines are used to illustrate environmental structure and form no part of the claimed design. 

The ornamental design for a flow regulator, as shown and described. 